A method, device and equipment for reducing signal shadow fading using dual antennas

Abstract

The present application relates to the field of wireless communications, and discloses a method, device and equipment for reducing signal shadow fading by using dual antennas. The method includes: setting a polling cycle through a TDMA networking system, wherein at least two special time slots are preset; the ground end sends the same data packet in the special time slot; the sky end receives the data packet through the first antenna and the second antenna respectively, and calculates the signal-to-noise ratio of each antenna; compares the signal-to-noise ratios of the two antennas, and selects the antenna with a larger signal-to-noise ratio as the working antenna in the subsequent time slot; at the end of each polling cycle, repeats the antenna selection process. The device includes two antennas, a T / R component, a single-pole double-throw switch and a baseband circuit, and the baseband circuit is responsible for analyzing the signal-to-noise ratio, controlling antenna switching and executing dynamic antenna selection logic. The present invention can effectively reduce the impact of signal shadow fading, improve the stability of the communication system, adapt to the dynamic channel environment, and optimize the cost, power consumption and reliability of communication equipment.

Description

Technical Field

[0001] The present invention relates to the field of wireless communication technology, and in particular to a method, device and equipment for reducing signal shadow fading by using dual antennas. Background Art

[0002] For the application scenario of wireless communication between small aircraft and the ground, the installation location of its external antenna is easily restricted due to the small size and compact structure of the aircraft. Generally, no matter whether the single antenna is installed on the nose, tail, belly or back of the aircraft, the aircraft body will block the signal reception of the antenna. This blocking effect will cause shadow fading, which will significantly reduce the quality of signal reception and seriously affect the stability of communication.

[0003] In order to deal with the shadow fading problem, the existing technology generally adopts a dual-antenna solution to optimize the signal at the receiving end or the transmitting end through spatial diversity, signal processing or coding technology. For example, by installing multiple antennas at different locations and using spatial diversity technology to receive multipath signals, the impact of shadow fading can be reduced to a certain extent. In addition, through Maximum Ratio Combining (MRC) or Selection Combining (Selection Combining) technology, the signal quality of multiple antennas can be integrated at the receiving end, and the best antenna can be selected or the signal can be weighted and synthesized according to the signal-to-noise ratio, thereby improving communication reliability.

[0004] Although these methods can effectively reduce shadow fading in theory, there are still many limitations in practical applications. First, these technologies usually require independent signal processing circuits for each antenna, including low-noise amplifiers, mixers, and baseband circuits, which significantly increases hardware complexity and system costs. Especially for dual-antenna communication equipment, two independent T / R components are required. This architecture is not only large in size and high in power consumption, but also poses severe challenges to space and energy-constrained devices such as small aircraft.

[0005] Secondly, existing signal processing algorithms have limitations in dynamic channel environments. For example, during the movement of an aircraft, channel characteristics can change rapidly with flight attitude, ground obstacles, or multipath interference. Traditional antenna selection or synthesis methods may have difficulty adapting to these changes in real time due to switching delays and algorithm complexity, thus affecting the stability of communications. Summary of the invention

[0006] In view of the shortcomings of the prior art, the present invention provides a method, device and equipment for reducing signal shadow fading by using dual antennas, which solves the problem of signal shadow fading caused by body obstruction or dynamic channel changes in wireless communications of existing small aircraft and other equipment, and provides a low-cost, low-power and highly adaptable dual-antenna dynamic selection solution.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions: A method for reducing signal shadow fading using dual antennas, comprising the following steps:

[0008] A polling cycle is set through the TDMA networking system, wherein the polling cycle includes a plurality of time slots and at least two special time slots are preset;

[0009] The ground terminal sends data packets in the two special time slots;

[0010] The air end receives the data packet through the first antenna and the second antenna respectively, and calculates a first signal-to-noise ratio of the signal received by the first antenna and a second signal-to-noise ratio of the signal received by the second antenna respectively;

[0011] Compare the first signal-to-noise ratio and the second signal-to-noise ratio, and select the antenna with the larger signal-to-noise ratio as the working antenna for data transmission and reception in the subsequent time slot;

[0012] At the end of each polling period, the above antenna selection process is repeated.

[0013] Preferably, the two special time slots are consecutively allocated time slots within the polling cycle.

[0014] Preferably, the number of time slots in the polling cycle is not less than three, wherein at least one non-special time slot is used for data exchange between the ground terminal and the sky terminal.

[0015] Preferably, the data packets sent by the ground terminal in the two special time slots have the same content and include a preset synchronization header, a payload and a check field.

[0016] Preferably, the calculation of the first signal-to-noise ratio and the second signal-to-noise ratio comprises the following steps:

[0017] Perform gain adjustment on the received signal to stabilize the signal power within a predetermined range;

[0018] Record the gain value after gain adjustment , and combined with the receive gain and antenna gain Calculate received signal power , the calculation formula is:

[0019]

[0020] According to the received signal power and noise power Calculate signal-to-noise ratio , the calculation formula is:

[0021]

[0022] The above steps are performed on the first antenna and the second antenna respectively to obtain a first signal-to-noise ratio and a second signal-to-noise ratio.

[0023] Preferably, in each of the polling cycles, the single-pole double-throw switch is controlled by the baseband circuit to switch between the first antenna and the second antenna.

[0024] The present invention also provides a communication device for reducing signal shadow fading, comprising:

[0025] Two antennas;

[0026] a T / R assembly;

[0027] a single-pole double-throw switch to switch between the two antennas;

[0028] Baseband circuitry for performing the following operations:

[0029] Control the single-pole double-throw switch to switch to the target antenna;

[0030] Analyze the signal-to-noise ratio of the signals received by the two antennas;

[0031] According to the comparison result of the signal-to-noise ratio, the working antenna for receiving data in the next round is determined.

[0032] Preferably, the two antennas have the same gain and are respectively installed at different positions of the device body.

[0033] Preferably, the single-pole double-throw switch is a radio frequency integrated switch, which is integrated with the T / R component in the same circuit module.

[0034] The present invention also provides a terminal device, comprising:

[0035] Equipment body;

[0036] a communication device mounted on the device body, wherein the communication device includes two antennas, a T / R assembly, a single-pole double-throw switch, and a baseband circuit;

[0037] The communication device executes the method to achieve reduction of signal shadow fading.

[0038] The present invention provides a method, device and apparatus for reducing signal shadow fading by using dual antennas. It has the following beneficial effects:

[0039] 1. The present invention uses a dual-antenna dynamic selection mechanism to receive signals using two antennas and compare based on the signal-to-noise ratio, and selects the antenna with a larger signal-to-noise ratio as the working antenna in each polling cycle. Through dynamic adjustment, the signal shadow fading caused by device body occlusion or complex environment can be significantly reduced, ensuring the stability and reliability of communication.

[0040] 2. The present invention uses a single set of T / R components combined with a single-pole double-throw switch to achieve dynamic switching of dual-antenna signals. Compared with the traditional dual-antenna design in which each antenna is configured with an independent T / R component, the present invention effectively reduces the hardware resource requirements, reduces the manufacturing cost and volume of the equipment, and provides support for miniaturization and integrated design.

[0041] 3. The present invention uses a dynamic antenna selection mechanism in a polling cycle to enable the terminal device to adapt to changes in the channel environment in real time. For example, when the channel conditions fluctuate due to aircraft movement or user movement, the device can quickly adjust the working antenna and always select the path with the best signal-to-noise ratio to ensure communication quality.

[0042] 4. The dual-antenna dynamic selection method and communication device design of the present invention are applicable to a variety of wireless communication scenarios, such as small aircraft, mobile terminals and fixed communication equipment. Its flexible design is compatible with different antenna configurations and communication protocols, and has good versatility and scalability.

[0043] 5. The present invention adopts a method of signal-to-noise ratio calculation and comparison, and ensures the accuracy of signal-to-noise ratio evaluation by combining a signal processing mechanism of gain adjustment and noise power measurement. The special time slot allocation design in the polling cycle ensures the efficiency of signal evaluation and provides reliable data support for fast antenna selection. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a schematic diagram of the method flow of the present invention;

[0045] Figure 2 A schematic diagram of the time slot structure in the TDMA networking system of the present invention;

[0046] Figure 3 It is a schematic diagram of the structure of the communication device of the present invention. DETAILED DESCRIPTION

[0047] The following will be combined with the drawings in the specification of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0048] Please refer to the attached Figure 1 -Attached Figure 2The present invention provides a method for reducing signal shadow fading by using dual antennas, which is applicable to wireless communication equipment such as small aircraft, and aims to solve the signal fading problem caused by body shielding or signal shadow of a single antenna. By combining the design of dual antennas with TDMA (time division multiple access) networking system, the signal reliability is improved and the energy consumption of the equipment is optimized. The steps of the present invention are described in detail below.

[0049] S1. Set polling cycle and special time slot through TDMA networking system

[0050] In the present invention, the TDMA (time division multiple access) networking system is used as the basic framework of communication. By dividing the communication process into polling cycles of fixed duration, the communicating parties can exchange data according to the preset time slot structure. In general, the setting of the polling cycle should meet the requirements of system communication frequency, signal evaluation and resource allocation, and be optimized according to the application scenario.

[0051] like Figure 2 As shown, in this embodiment, the polling cycle in the TDMA networking system is divided into multiple time slots, each of which has a fixed duration and is allocated in a predetermined order. The specific length of the polling cycle is determined by the requirements of the communication system. For example, in some embodiments, the polling cycle can be set to 1ms to 10ms, depending on the data transmission rate and delay requirements.

[0052] Generally, the number of time slots in each polling cycle is not less than three to ensure basic data transmission requirements during the communication process. At the same time, in order to implement antenna signal quality evaluation, the present invention presets at least two special time slots in the polling cycle.

[0053] As an option, the special time slot can be preferentially arranged at the front or end of the polling cycle. For example, in one possible implementation, the polling cycle consists of five time slots, of which the first and second time slots are special time slots, and the third to fifth time slots are used for normal communication. This arrangement can adjust the antenna immediately after evaluating the signal quality, improving the dynamic adaptability of communication.

[0054] Specifically, the special time slots are used for the ground end to send signals for the sky end to evaluate the signal quality. In this embodiment, the time length of these special time slots should be consistent with the normal time slots, usually between 100µs and 1ms, and the specific length can be optimized according to the system bandwidth and data packet size.

[0055] In some embodiments, the special time slots are allocated consecutively, for example, two consecutive time slots in a polling cycle (e.g. and ) is set as a special time slot. This continuous allocation method can reduce the timing error of antenna switching and improve the efficiency of signal evaluation.

[0056] As an option, the allocation of special time slots can also be non-continuous. For example, in one possible implementation, the first time slot and the last time slot in the polling cycle are set as special time slots to evaluate the quality difference of the signal in different time periods. This allocation is suitable for application scenarios where the channel environment changes rapidly.

[0057] In one possible implementation, the time slot allocation of the polling cycle can be dynamically adjusted to adapt to the actual communication environment. For example, in a scenario with large signal interference, the proportion of special time slots in the polling cycle can be increased to provide more signal evaluation opportunities; while in a scenario with good channel stability, the special time slots can be reduced to improve data transmission efficiency.

[0058] Specifically, the dynamic adjustment of special time slots can be accomplished through the baseband circuit, which calculates the number and allocation positions of special time slots required in each polling cycle based on historical signal quality data, and dynamically updates the time slot structure through control signals.

[0059] As an extended technology, special time slots can not only be used for signal quality assessment, but also for system synchronization, error correction and other functions. For example, in a special time slot, the ground end can send a synchronization signal with a special code type, and the sky end can complete signal synchronization and signal-to-noise ratio calculation at the same time after receiving it, thereby further improving the efficiency of the communication system.

[0060] The above is a detailed description of step S1, which ensures the reliability of signal evaluation and the real-time performance of antenna switching by reasonably designing the polling cycle and special time slot allocation of the TDMA networking system, thus laying a foundation for the implementation of other steps of the present invention.

[0061] S2. The ground terminal sends a data packet

[0062] In the present invention, the ground end is responsible for sending data packets to the sky end in a preset special time slot for signal quality assessment and antenna selection. Generally, the data packets sent by the ground end in these time slots should be consistent to avoid interference from data content differences on signal quality assessment. The data packet content must meet the requirements of signal analysis, signal-to-noise ratio calculation and verification, and the packet header, payload and verification field must be reasonably designed.

[0063] As an option, the content of the data packet can include a specific frame synchronization pattern so that the sky end can quickly lock the signal and complete demodulation. Specifically, these data packets can consist of a fixed format data structure, which contains a preset synchronization header, payload and check field. The main function of the synchronization header is to achieve frame synchronization of the data packet, while the payload contains data for signal evaluation.

[0064] In this embodiment, the ground terminal sends a data packet in each of the two special time slots, and the contents of the two data packets are exactly the same. This design can effectively reduce the impact of the data packet content on the signal-to-noise ratio evaluation result and ensure the accuracy of the signal quality evaluation.

[0065] As an option, the format of the data packet consists of the following three parts:

[0066] Synchronization header: used to achieve frame synchronization of data packets, so that the sky end can quickly lock the signal;

[0067] Payload: Carries specific data for signal quality assessment;

[0068] Verification field: used to verify the integrity of the data packet and ensure the reliability of the evaluation results.

[0069] Specifically, the synchronization header may adopt a pseudo-random pattern or a fixed pattern, such as a binary sequence of 8 or 16 bits in length, which has the characteristics of high correlation and low autocorrelation. In a possible implementation, the length of the synchronization header may be adjusted according to the communication bandwidth, such as using a shorter synchronization header in narrowband communication and using a longer synchronization header in broadband communication to enhance the synchronization effect.

[0070] In this embodiment, the payload is mainly used to carry signal evaluation data, and its content may include a fixed-mode bit sequence or a test signal of a specific frequency. In some embodiments, the payload may be designed as a specific code sequence that is repeatedly sent so that the sky end can perform statistical analysis on the signal characteristics during the demodulation process, thereby more accurately calculating the signal-to-noise ratio.

[0071] As a possible choice, the length of the payload is usually designed to be the smallest data block unit that the system can handle, such as a 64-bit, 128-bit or 256-bit data frame. The specific choice depends on the bandwidth and processing power of the communication system.

[0072] Generally, the check field is used to verify the integrity of the data packet to ensure that the received data is not damaged or lost during the transmission process. In this embodiment, the check field can be generated using a cyclic redundancy check (CRC) method. For example, for a 16-bit CRC check, the generating polynomial can be , which has high verification efficiency and can detect multiple types of data errors.

[0073] As a possible implementation, a check field can be appended to the end of the data packet, and the check value can be calculated by hardware or software at the air end to verify the integrity and correctness of the data packet.

[0074] In some embodiments, the transmission power of the ground end can be dynamically adjusted according to the communication distance and signal strength. For example, when the communication distance is far or the signal strength is low, the ground end can increase the transmission power to enhance the signal strength, thereby ensuring that the sky end can accurately receive and parse the data packet.

[0075] In one possible implementation, the transmission power of the ground end can be adjusted in real time by the system control module. For example, the ground end can dynamically adjust the transmission power to adapt to the current communication environment based on the received antenna selection feedback information. This design can further improve the robustness and adaptability of the communication system.

[0076] Through the above technical design, the present invention realizes efficient data transmission at the ground end in a special time slot in step S2, and ensures the accuracy of signal evaluation and the reliability of antenna selection through reasonable data packet design and transmission power adjustment.

[0077] S3, the sky end receives and calculates the signal-to-noise ratio

[0078] In the present invention, the dual antenna system of the sky end is responsible for receiving two data packets from the ground end, and respectively analyzing and calculating the signal-to-noise ratio to determine the signal quality. Generally, the calculation of the signal-to-noise ratio needs to be based on the power of the received signal and the noise power. By comparing the signal-to-noise ratio results of the two antennas, the best working antenna can be selected.

[0079] As an option, the calculation of the signal-to-noise ratio can be completed by the baseband circuit of the sky end. Specifically, after the received signal is processed by the antenna, T / R components and baseband circuit, the signal power and noise power are extracted and the signal-to-noise ratio value is calculated. The present invention lays a foundation for subsequent antenna selection through a reasonable signal-to-noise ratio calculation and comparison process.

[0080] In this embodiment, the sky end receives the same data packet sent by the ground end through the first antenna and the second antenna in two special time slots of each polling cycle. Specifically, when the first special time slot arrives, the sky end receives the signal through the first antenna; and when the second special time slot arrives, the sky end switches to the second antenna to receive the signal.

[0081] As a possible implementation, the switching of the antennas is completed by the baseband circuit controlling the single-pole double-throw switch. Generally, the baseband circuit completes the antenna switching between special time slots through a control signal, thereby ensuring that the two antennas can respectively receive complete data packets.

[0082] In some embodiments, the signal received by the antenna is first low-noise amplified by the T / R component and then transmitted to the baseband circuit. The baseband circuit is responsible for demodulating the received signal and analyzing the signal power. and noise power , to calculate the signal-to-noise ratio.

[0083] Specifically, it is assumed that the power of the effective signal (signal that can be demodulated) received by the antenna is (Unit: dBm), the ambient noise power is (unit: dBm), the antenna gain is (Unit: dB), receiving gain of T / R component (Unit: dB), gain of the AGC (automatic gain control) module (Unit: dB);

[0084] Reasonable AGC algorithm design ensures that the signal power after passing through the AGC module will be stabilized at 0dBm, and the AGC module will output the current gain ;

[0085] but

[0086]

[0087]

[0088] Assume that the power of the effective signal received by the first antenna is , the corresponding AGC module gain is ; Assume that the power of the effective signal received by the second antenna is , the corresponding AGC module gain is ,but

[0089] (1)

[0090] (2)

[0091] According to formula (1) and formula (2), we can know

[0092] (3)

[0093] According to formula (3), we can know that , The size of and size.

[0094] In this embodiment, the signal power The calculation of includes the following steps:

[0095] The gain of the received signal is adjusted to stabilize the signal power within a predetermined range, such as 0 dBm.

[0096] Record the gain value after gain adjustment , and combined with the receive gain and antenna gain , the signal power is calculated by the following formula:

[0097]

[0098] In some embodiments, gain adjustment may be implemented through an automatic gain control module (AGC), which is capable of dynamically adjusting signal gain to adapt to different channel conditions and signal strengths.

[0099] As an option, the noise power It can be obtained through device calibration or the noise measurement module of the baseband circuit. In general, the noise power value depends on the noise level of the receiving environment and the built-in noise characteristics of the device.

[0100] Signal-to-Noise Ratio The calculation formula is:

[0101]

[0102] in, is the effective power of the received signal, is the noise power. This formula can accurately reflect the signal quality and thus provide a reliable basis for antenna selection.

[0103] In this embodiment, the sky end completes the above signal-to-noise ratio calculation through the data packets received by the first antenna and the second antenna respectively, and finally obtains the signal-to-noise ratio of the first antenna. and the signal-to-noise ratio of the second antenna .

[0104] In one possible implementation, the result of the SNR calculation is stored in a register of the baseband circuit for comparison and antenna selection in subsequent steps. As an option, the baseband circuit can also average or filter the SNR result to reduce the impact of short-term channel fluctuations on the evaluation result.

[0105] Through the above design, the present invention realizes the complete process of dual-antenna signal reception and signal-to-noise ratio calculation in step S3, providing reliable technical support for subsequent antenna selection.

[0106] S4. Antenna selection

[0107] In the present invention, by comparing the signal-to-noise ratio of the signals received by the first antenna and the second antenna, the antenna with a larger signal-to-noise ratio is dynamically selected as the working antenna for subsequent communication. In general, the selection of the antenna needs to be based on the size of the signal-to-noise ratio. This process can effectively reduce the impact of signal shadow fading and optimize communication performance.

[0108] As an option, the comparison of the signal-to-noise ratio can be automatically completed by the baseband circuit, and the antenna with a larger signal-to-noise ratio is set as the working antenna in the subsequent time slot. Specifically, the antenna will take on the task of receiving and sending the next round of data.

[0109] In this embodiment, the sky end calculates the signal-to-noise ratio of the first antenna and the second antenna in two special time slots, respectively, and is recorded as and The baseband circuit compares the two signal-to-noise ratios and selects the working antenna based on the following logic:

[0110] if , then the first antenna is selected as the working antenna;

[0111] if , then the second antenna is selected as the working antenna.

[0112] As a possible implementation, the comparison of the signal-to-noise ratio can be implemented by a simple comparison operator, for example, by performing a difference operation on the signal-to-noise ratio values ​​in two signal registers to determine the size.

[0113] Specifically, the antenna selection logic is completed by the baseband circuit through the control signal. Generally, the baseband circuit generates a signal for controlling the single-pole double-throw switch at the end of the current polling cycle to switch the switch to the target antenna. In some embodiments, in order to reduce the switching timing delay, the baseband circuit generates a control signal immediately after the comparison result is generated to ensure that the target antenna can be connected in time.

[0114] As an option, the baseband circuit can implement fast comparison through hardware logic circuits, or can complete the logical judgment of the signal through software algorithms. In a possible implementation, the time consumption of the signal-to-noise ratio comparison is controlled at the microsecond level to ensure the real-time performance of the antenna switching.

[0115] In this embodiment, in order to improve the reliability of antenna selection, the baseband circuit can filter the signal-to-noise ratio data. For example, a weighted average method is used to fuse the signal-to-noise ratio results of the current polling cycle and the historical polling cycle, thereby reducing the impact of short-term channel fluctuations on antenna selection.

[0116] In some embodiments, the comparison result of the signal-to-noise ratio may be stored in a non-volatile memory so as to quickly restore the configuration state of the target antenna when the device is restarted or the communication is interrupted.

[0117] As a further optimization design, the baseband circuit can monitor the efficiency of the antenna selection process. If multiple consecutive antenna switches fail to significantly improve the signal quality, the baseband circuit can temporarily lock the current working antenna to reduce unnecessary switching operations.

[0118] In one possible implementation, the frequency of antenna selection can be adapted to the channel state. For example, when the channel condition is relatively stable, antenna selection can be performed once after multiple polling cycles; when the channel condition fluctuates violently, antenna selection can be performed once per polling cycle, thereby implementing an adaptive antenna management strategy.

[0119] Through the above design, the present invention implements a dynamic antenna selection logic based on signal-to-noise ratio comparison in step S4, providing reliable signal quality assurance for subsequent communication processes.

[0120] S5: Repeat the above process within the polling cycle

[0121] In the present invention, the antenna selection process needs to be repeated at the end of each polling cycle to adapt to the dynamically changing communication environment and channel status. In general, the quality of the channel will be affected by factors such as the external environment, the movement state of the device, and the interference source. Therefore, through periodic antenna selection, the working antenna can be dynamically adjusted to ensure the stability of communication.

[0122] As an option, the antenna selection at the end of the polling cycle can be automatically triggered by the baseband circuit. Specifically, after the baseband circuit detects that the last time slot of the polling cycle has completed, it will start a new signal-to-noise ratio calculation and comparison process and apply the result to the antenna configuration of the next polling cycle.

[0123] In this embodiment, the baseband circuit of the sky end re-evaluates the signal-to-noise ratio of the first antenna and the second antenna at the end of the current polling cycle. Specifically, the baseband circuit calculates the signal-to-noise ratio according to the latest received data packet, and compares it with the signal-to-noise ratio result of the previous cycle to determine whether the currently selected working antenna needs to be switched.

[0124] Generally, if the signal-to-noise ratio of the currently operating antenna is significantly lower than that of another antenna, the baseband circuit generates a control signal to switch the single-pole double-throw switch to the antenna with a higher signal-to-noise ratio to ensure optimal signal quality in the next polling cycle.

[0125] In some embodiments, the baseband circuit will refer to multiple rounds of historical signal-to-noise ratio data at the same time and calculate the comprehensive performance index of the antenna through weighted average or filtering algorithm. The signal-to-noise ratio data of the polling cycle, the comprehensive performance index can be calculated as:

[0126]

[0127] This design can smooth the impact of short-term channel fluctuations and improve the reliability of antenna selection.

[0128] As a possible implementation, the antenna selection logic at the end of the polling cycle can be implemented using a state machine control method. Specifically, the baseband circuit can preset three states: keep the current antenna, switch to the first antenna, and switch to the second antenna. According to the result of the signal-to-noise ratio comparison, the state machine automatically switches to the target state to control the antenna switching operation.

[0129] To further optimize performance, in this embodiment, at the end of each polling cycle, the selection result of the current antenna is also stored. For example, the baseband circuit stores the signal quality indicator and selection result of the currently selected antenna in a non-volatile memory so as to quickly restore the antenna configuration after the device is restarted or the communication is interrupted.

[0130] In some embodiments, in order to reduce unnecessary antenna switching operations, a signal-to-noise ratio switching threshold can be set. Specifically, the antenna switching operation is triggered only when the difference in the signal-to-noise ratio of the two antennas exceeds a preset threshold. For example, the preset threshold can be 2 dB, that is, only when This design can effectively avoid frequent switching when the signal-to-noise ratio is close, thereby reducing communication delays and device energy consumption.

[0131] As a further optimization, this embodiment also supports dynamic adjustment of the polling cycle length. For example, when it is detected that the channel stability is high, the polling cycle can be appropriately extended to reduce the antenna selection frequency; and when the channel fluctuation is large, the polling cycle can be shortened to improve the timeliness of antenna adjustment.

[0132] Through the above design, the present invention implements dynamically adjusted antenna selection logic in step S5, and ensures the accuracy and efficiency of the antenna selection process through signal-to-noise ratio evaluation, historical data reference and switching threshold control.

[0133] In general, the present invention divides the communication process into multiple polling cycles through the TDMA networking system, and presets a special time slot in each polling cycle. The ground end sends the same data packet, and the sky end receives and calculates the signal-to-noise ratio through dual antennas. Based on the signal-to-noise ratio comparison result, the antenna with a larger signal-to-noise ratio is dynamically selected as the working antenna in the subsequent time slot, thereby effectively reducing the impact of signal shadow fading on communication.

[0134] Please refer to the attached Figure 3 The present invention also provides a communication device for reducing signal shadow fading. The device effectively realizes the function of dynamic selection of dual antennas through hardware architecture design and signal processing logic, and is suitable for wireless communication scenarios in complex channel environments. The structure and function of the communication device are described in detail below.

[0135] The communication device includes the following main components:

[0136] Two antennas: installed at different locations on the device to receive and send wireless signals;

[0137] T / R component: responsible for sending, receiving and amplifying signals to ensure signal quality;

[0138] SPDT switch: used to switch the signal paths of the two antennas and connect the target antenna to the T / R assembly;

[0139] Baseband circuit: used for signal analysis and antenna selection, including control module and signal processing module.

[0140] Generally, the two antennas have the same gain and are placed at different locations on the communication device to reduce the shielding of the device body to the signal. For example, in a small aircraft, the antennas can be placed at the nose and tail to ensure signal coverage in different directions.

[0141] In this embodiment, the T / R component is responsible for transmitting and receiving signals, including low noise amplification, down conversion and RF signal processing. Specifically:

[0142] In the receiving mode, the T / R component receives the signal switched from the antenna and performs low-noise amplification on the signal;

[0143] In the transmit mode, the T / R component receives the signal output by the baseband circuit, converts it into a high-frequency signal, and then transmits it through the target antenna.

[0144] As an option, the T / R assembly can be integrated with the SPDT switch in an RF front-end module, thus simplifying the hardware design and reducing the size of the device.

[0145] In this embodiment, the single-pole double-throw switch is used to switch the signal path between the two antennas, the input end of which is connected to the T / R component, and the two output ends are connected to the first antenna and the second antenna respectively.

[0146] The baseband circuit controls the switching state of the single-pole double-throw switch through a control signal;

[0147] In a special time slot, the single-pole double-throw switch switches to the target antenna according to the instruction of the baseband circuit to receive the signal;

[0148] In the normal time slot, the single-pole double-throw switch is fixedly connected to the selected working antenna to ensure the continuity of data transmission.

[0149] In some embodiments, the single-pole double-throw switch may adopt a radio frequency integrated switch, which has low power consumption and fast switching speed and can meet high-frequency switching requirements.

[0150] The baseband circuit is the core module of the communication device, responsible for executing signal analysis and antenna selection logic. Specifically, the baseband circuit includes a control module and a signal processing module.

[0151] Among them, the control module:

[0152] generating a control signal to instruct the single-pole double-throw switch to switch to the target antenna;

[0153] According to the time allocation of the polling cycle, the switching of antennas is scheduled in real time.

[0154] Among them, the signal processing module:

[0155] Receive the signal output by the T / R component and analyze the signal-to-noise ratio of the signal;

[0156] Calculate the signal quality according to the signal-to-noise ratio calculation formula of the aforementioned method embodiment;

[0157] The signal-to-noise ratios of the two antennas are compared, and the antenna with the larger signal-to-noise ratio is determined as the working antenna for the next round of receiving data.

[0158] In some embodiments, the baseband circuit can also filter the signal-to-noise ratio data to reduce the impact of channel fluctuations on antenna selection. For example, the baseband circuit can use a weighted average method to fuse the signal-to-noise ratio data of historical polling cycles to improve the stability of the evaluation.

[0159] This device dynamically executes antenna selection logic through baseband circuits. The specific implementation method includes the following steps:

[0160] In a special time slot of the polling cycle, the baseband circuit instructs the single-pole double-throw switch to switch to the first antenna, receive the signal and calculate the signal-to-noise ratio;

[0161] In the next special time slot, the baseband circuit instructs the single-pole double-throw switch to switch to the second antenna, receive the signal and calculate the signal-to-noise ratio;

[0162] Compare the signal-to-noise ratios of the two antennas and determine the antenna with the larger signal-to-noise ratio as the working antenna for the next round of data transmission and reception;

[0163] The antenna selection result is stored in a register and a control signal is sent to a single-pole double-throw switch to complete the antenna switching.

[0164] In some embodiments, in order to avoid communication delays caused by frequent switching, the baseband circuit can set a signal-to-noise ratio switching threshold. For example, antenna switching is triggered only when the difference in signal-to-noise ratio between the two antennas exceeds 2 dB.

[0165] In a possible implementation, the communication device is applied to a small aircraft wireless communication scenario:

[0166] During flight, the aircraft may block the antenna signal.

[0167] The baseband circuit analyzes the signal quality in real time and dynamically switches the antenna via a single-pole double-throw switch;

[0168] When the aircraft's attitude changes, the baseband circuit automatically adjusts the working antenna to ensure that the signal quality is always in the best condition.

[0169] Through the above design, the communication device of the present invention combines the coordinated work of dual antennas, T / R components, single-pole double-throw switches and baseband circuits to effectively reduce signal shadow fading. The device has a compact structure and low power consumption, and is suitable for a variety of complex communication environments.

[0170] The present invention also provides a terminal device, which can effectively reduce the influence of signal shadow fading in a dynamic channel environment by integrating the aforementioned communication device and executing the signal processing method. The terminal device of the present invention is compact in design and is suitable for small aircraft, mobile communication terminals or other wireless communication device scenarios. The specific implementation method thereof is described in detail below.

[0171] This terminal device consists of the following parts:

[0172] Equipment body: provides the physical support structure of the terminal equipment for installing communication devices and other functional components;

[0173] Communication device: installed on the main body of the device, including two antennas, a T / R assembly, a single-pole double-throw switch and a baseband circuit, responsible for signal reception, processing and dynamic antenna selection;

[0174] Implementation method: The communication device implements the aforementioned signal shadow fading reduction method to achieve dynamic antenna selection to optimize communication quality.

[0175] Generally speaking, the device body can be designed as an aircraft body, a portable device housing or a fixed installation device according to different application scenarios. For example, in a small aircraft, the device body is usually the fuselage structure of the aircraft, and its design needs to take into account the requirements of light weight and high space utilization.

[0176] In this embodiment, the communication device is installed on the device body, wherein the two antennas are arranged at different positions of the body. Specifically:

[0177] In an aircraft scenario, the first antenna can be installed at the nose and the second antenna at the tail;

[0178] In the mobile communication terminal scenario, two antennas can be arranged at the top and bottom of the device respectively to ensure directional coverage of signal reception.

[0179] Generally, the installation positions of the two antennas should minimize the shielding of the device body to signal propagation, while optimizing the signal independence between the antennas. In some embodiments, the gain of the antennas can be designed to be the same value, such as 2dBi or 5dBi, to ensure consistency in signal evaluation.

[0180] In this embodiment, the communication device includes:

[0181] T / R component: responsible for receiving and sending signals. In the receiving mode, it performs low-noise amplification and down-conversion processing on the signal; in the transmitting mode, it modulates the baseband signal into a high-frequency signal and sends it through the antenna.

[0182] SPDT switch: used to switch the signal path between the two antennas. Its input is connected to the T / R component and its output is connected to the two antennas. The baseband circuit realizes the dynamic switching of the switch through the control signal.

[0183] Baseband circuit: The core processing unit responsible for performing the following operations:

[0184] Control the single-pole double-throw switch to switch the antenna;

[0185] Analyze the signal-to-noise ratio of the signals received by the two antennas;

[0186] Compare the signal-to-noise ratios and determine the working antenna.

[0187] As an option, the communication device can be integrated with the device body through modular design. For example, the core module of the communication device can be packaged as an independent circuit board to facilitate rapid deployment and maintenance of the device.

[0188] The terminal device executes the aforementioned signal shadow fading reduction method through a communication device, and its working process includes the following steps:

[0189] In this embodiment, after the device is started, the communication device enters a polling cycle and receives signals sent by the ground end through two antennas in a special time slot of each cycle.

[0190] The baseband circuit analyzes the received signal and calculates the signal-to-noise ratio of the two antennas respectively, and the calculation formula is as described in the above method.

[0191] The baseband circuit compares the signal-to-noise ratios of the two antennas and controls the single-pole double-throw switch to switch to the antenna with a larger signal-to-noise ratio based on the signal-to-noise ratio result, setting it as the working antenna for subsequent data transmission.

[0192] After the polling cycle ends, the communication device repeats the above antenna selection logic to dynamically adapt to changes in the channel environment and ensure the stability of communication.

[0193] In this embodiment, the terminal device is suitable for the following application scenarios:

[0194] In small aircraft, terminal devices dynamically select antennas to reduce the impact of body obstruction and signal shadowing, thereby ensuring the reliability of communication with the ground station during flight.

[0195] In mobile communication terminals, the device can adapt to channel changes caused by user movement, optimize signal quality through dual antenna switching, and improve communication performance.

[0196] In fixed communication scenarios, such as communication between a base station and a remote device, the terminal device uses a dual-antenna selection mechanism to enhance the system's adaptability to multipath interference.

[0197] Through the above design, the terminal device of the present invention is combined with the dynamic antenna selection method of the communication device to achieve effective reduction of signal shadow fading, adapt to a variety of complex communication environments, and has wide application value.

[0198] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for reducing signal shadow fading using dual antennas, characterized in that: The following steps are involved: A polling cycle is set through the TDMA networking system, wherein the polling cycle includes a plurality of time slots and at least two special time slots are preset; The ground terminal sends data packets in the two special time slots; The air end receives the data packet through the first antenna and the second antenna respectively, and calculates a first signal-to-noise ratio of the signal received by the first antenna and a second signal-to-noise ratio of the signal received by the second antenna respectively; Compare the first signal-to-noise ratio and the second signal-to-noise ratio, and select the antenna with the larger signal-to-noise ratio as the working antenna for data transmission and reception in the subsequent time slot; At the end of each polling cycle, the special time slot data reception, signal-to-noise ratio calculation and antenna selection steps are re-executed; The two special time slots are consecutively allocated time slots in the polling cycle; The calculation of the first signal-to-noise ratio and the second signal-to-noise ratio comprises the following steps: Perform gain adjustment on the received signal to stabilize the signal power within a predetermined range; Record the gain value after gain adjustment , and combined with the receive gain and antenna gain Calculate received signal power , the calculation formula is: ； According to the received signal power and noise power Calculate signal-to-noise ratio , the calculation formula is: ； The above steps are performed on the first antenna and the second antenna respectively to obtain a first signal-to-noise ratio and a second signal-to-noise ratio.

2. The method for reducing signal shadow fading using dual antennas according to claim 1, characterized in that: The number of time slots in the polling cycle is not less than three, and at least one non-special time slot is used for data exchange between the ground terminal and the sky terminal.

3. The method for reducing signal shadow fading using dual antennas according to claim 1, characterized in that: The data packets sent by the ground terminal in the two special time slots have the same content and include a preset synchronization header, a payload and a check field.

4. The method for reducing signal shadow fading using dual antennas according to claim 1, characterized in that: In each of the polling cycles, the single-pole double-throw switch is controlled by the baseband circuit to switch between the first antenna and the second antenna.

5. A communication device for implementing the method according to any one of claims 1 to 4 to reduce signal shadow fading, characterized in that: include: Two antennas; a T / R assembly; a single-pole double-throw switch to switch between the two antennas; Baseband circuitry for performing the following operations: Control the single-pole double-throw switch to switch to the target antenna; Analyze the signal-to-noise ratio of the signals received by the two antennas; According to the comparison result of the signal-to-noise ratio, the working antenna for receiving data in the next round is determined.

6. A communication device for reducing signal shadow fading according to claim 5, characterized in that: The two antennas have the same gain and are respectively installed at different positions of the device body.

7. A communication device for reducing signal shadow fading according to claim 5, characterized in that: The single-pole double-throw switch is a radio frequency integrated switch and is integrated with the T / R component in the same circuit module.

8. A terminal device, characterized in that: include: Equipment body; a communication device mounted on the device body, wherein the communication device includes two antennas, a T / R assembly, a single-pole double-throw switch, and a baseband circuit; The communication device executes the method according to any one of claims 1 to 4 to reduce signal shadow fading.

Images